We all have to remember we are talking fantasy here... and sometimes it does get a little dark, and maybe make one a tad uncomfortable, which isn't a bad thing, frankly.

Death being the ultimate in darkness. But like anything, it is in how it is used.
I've written stories both erotic and dramatic to lighthearted, with grim and happy endings and everything in between. (Thanks for the kind words for "Nikki", DJlurker... I'm hoping to bring her back one day for another sinking adventure).
Personally, I prefer grim endings in my dramatic stories, but not always. I like my qs traps to be of the harsh natural justice variety, as in, the baddie deserves it and vanishes, while the heroine/intended victim escapes. Or perhaps it is harsh karma - if said person wasn't such a jerk to everyone, maybe she'd have someone nearby to rescue her... that sort of thing.
I did do a story when a nice girl is murdered by being tossed into quicksand by some baddies.... only to return as a swamp guardian spirit who makes them regret that action. That is more of a superhero origin story, just with quicksand, but it is also hows death can fit into a qs narrative....
My erotic stuff, or sinking for the pleasure of it, is half and half... sometimes she goes out with a bang, so to speak...

or is able to get out so she can sink another time. In both cases, it is her actions which get her into trouble.... and sometimes she's okay with her grim fate if it comes to that. Romeo and Juliet like endings I'm very fond of, at times. In those cases, it is a choice the couple made together... (remember - this is fantasy, and not advocating suicide for real...)
My story Klaae, about a lady warrior being seduced and consumed by an erotic clay elemental taking the form of its previous victims, is for the reader to decide whether it is a sad fate or not. She certainly had a good time... and her soul lives on happily within the clay itself... although it is likely she will also take part in consuming the next victim to come along.
My point is, death itself isn't really "death" in the fantasy we are all working with, but an element of the tale being told. When we enjoy fiction and fantasy, and characters get killed off for the sake of the story, that is all it is. It isn't as if we would enjoy seeing people being killed in real life (I would hope not, anyway...) Not to belittle any serious concerns here, but to me, worrying about death in our fantasies is overthinking the concept a bit too much. But that is just my two cents.